Rock or earth drill



. 7 Sheets-Sheet 1.

(No Model.)

M. G. BULLOCK. ROCK AND EARTH DRILL.

No. 443,819. Patented Dec. 30,1890.

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(No Model.) 7 Sheets-Sheet 2. M. O. BULLOCK.

ROCK AND EARTH DRILL.

No. 443,819. Patented Dec. 30, 1890.

@fia au QM (No Model.) 7 Sheets-Sheet 3.

M. 0. BULLOCK. v ROCK AND EARTH DRILL.

Patented Dec. 30, 1890.

E a i 7 Sheets-Sheet 4.

(No Model.) I

M.0.BULLO0K. ROCK AND EARTH DRILL.

Patented De0.30,1890

if \i 1 m:

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7 Sheets-Sheet 5.

Patented'Deo. 30,1890,

(No Model.) 7 Sheets-Sheet 7.

M. 0. BULLOCK.

ROUK AND EARTH DRILL.

No. 443,819. Patented Dec. 30, 1890.

fJllmnllllllllllllll J3 UNITED STATES PATENT OFFICE.

MILAN C. BULLOCK, OF CHICAGO, ILLINOIS.

ROCK OR EARTH DRILL.

SPECIFICATION forming part of Letters Patent No. 443,519, dated December30, 1890.

Application filed March 16, 1883. Serial No. 267,293. (No model.)

To all whom it may concern:

Be it known that I, MILAN C. BULLOCK, of Chicago, in the county of Cookand State of Illinois, have invented certain new and useful Improvementsin Rock or Earth Drills; and I do hereby declare that the following is afull, clear, and exact description thereof, reference being had to theaccompanying drawings, and to the letters of reference marked thereon,which form a part of this specification.

This invention relates to a rock-drilling machine which, besides otherfeatures of improvement, accomplishes the insertion of the easing intothe hole at the same time that the drill or reamer is cutting the hole.

The invention here set forth consists in various matters hereinafterdescribed and claimed, and illustrated in one practical form in theaccompanying drawings.

In the drawings, Figure 1 is a front elevation of a machine embodying myimprovements. Fig. 2 is a vertical section from front to rear in theline 2 2 of Fig. 1. Fig. 3 is a side elevation of a bent water-feed tubeand its connection with the upper end of a section of a tubulardrill-rod which is driven by the machine. Fig. 4 is a vertical sectionof said water-feed tube and its connection with the tubular drill-rod.Fig. 5 is a side elevation of the swiveled frame of the machine with thedriving mechanism connected therewith, a portion of the shell of theswivelhead being broken away to reveal particularly the feed mechanismcontained therein, and the supports of the. horizontal shafts of thefeed mechanism being shown in vertical section from front to rear. Fig.6is a rear view of the swivel-frame and generally of the matters shown inFig. 5, so far as visible from the rear exterior, certain concealedparts being shown by dotted lines. Fig. 7 is a horizontal section in theline 7 7 of Figs. 1, 5, and 6, but on the scale of Figs. 5 and 6. Fig. 8is a vertical section of the roller-bearing seen in the lower part ofFig. 2 enlarged to a scale still larger than that of Figs. 5, 6, and 7.Fig. 9 1s a vertical section in the indirect line 9 9 of Fig. 7. Fig. 10is a vertical section in the line 10 1t) of Figs. 1 and 11, the sectionof Fig.10 be ng taken in the same plane in which the section of thebearings is taken in Fig. 5 and on the same scale. Fig. ll is atransverse section of parts shown in Fig. 10, taken upon line 11 11 ofsaid figure. Fig. 12 is a fragment of the hollow shaft and of thesliding key-shaft shown in side view in the upper part of Fig. 10. Fig.13 is a central vertical section running from front to rear in the line13 13 of Fig. 1 through the parts embracing the feedscrew, including thevertically movable splined clutch seen in Fig. 1 and the other partsbelow said clutch, being on the same scale as Fig. 5. The feed-screw isshown in side elevation. Fig. 14: is acentral vertical section of thelower end of the feed-screw, shown in side elevation in Fig. 13, and ofa swiveled chuck attached thereto and of a fragment in section of thecasing attached to the swiveled chuck. Fig. 15 is a side elevation ofthe machine-frame or swivel-head, together with the adjacent parts ofthe engineframe which supports it.

A is the swivel-plate or back plate of the swiveled frame, mounted,usually, on an engine-frame to turn on an axis coincident with that ofthe engine crank-shaft B, which is the only part of the engine or motormechanism here shown. To the swiveled plate A is hinged the swivel-headA in the usual manner, a in this intance being the hinge, and a, thelocking device by which the head A is fastened back against the platelAwhen the machine is ready for work. The head A constitutes a frame-workfor the support of the mechanism which sustains, guides, and operatesthe drill-rod and the feed-screw. The swivelhead is here shown as ashell open at the front, the top plate of which, made heavy and bossed,is lettered A The bottom plate thereof is marked A From the ends of thetop cross-plate A rise the parallel guide-pillars A A, tied together atthe top by a cross-girt a and having fitted thereto a sliding crossheadA In this cross head is rotatably mounted a sleeve E, carrying a fixedpinion e below and a driving-chuck F. above the cross-head. The chuck Eis of the usual or any suitable construction adapted to seize and turnthe drill-rod C. I

C Figs. 3 and 4:, is a bent water-feed tube which is connected with theupper end or sec tion of the tubular drill-rod C by a packed joint Cconstructed in the usual manner to ends, respectively.

below the swivel-head.

allow the rod to freelyturn while the pipe 0 remains stationary.

Below the pinion e the sleeveEalso carries a roller thrust-bearing E(best shown in Fig. 8,) constructed to take'either an upward or adownward thrust and provided in its lower end with a screw-thread totake the upper end. of the tubular feed-screw D.

F isa feed-nutorinteriorly-tln'eaded sleeve (see Fig. 9) fitted to thethread of the feedscrew D and rotatably supported in the crossplate Aof'the swivel-frame. The lower end. of the feed-nut is provided with afiangef, having marginal notches f, andv also'with clutch-teeth f Belowthe feed-nut a clutchsleeve G embraces the feed-screw, being providedwith teeth 9 g onits upper and lower This clutch is provided with aspline or feather which fits a longitudinal feather-way (Z in thefeed-screw, and therefore rotates or is rotated by said screw.

The clutch-sleeve G is allowed a vertical movement, which is given it bymeans of a hand-lever G, Fig. 1, the fixed fulcrum of which is beneaththe notched margin of the flange f on the sleeve-nut F. The hand-leveris provided with an arm G the end of which is adapted to enter a notch fin the flange f and will do so when the clutch-sleeve is depressed to orbelow its mid-position.

G is a set-screw device of obvious con struction, by which thehand-lever and clutchsleeve may be locked in any desired position.

Below the clutch-sleeve G the feed-screw D is embraced by anon-threadedloose sleeve or hub H,which carries a worm-wheel H, and the upper end ofsaid worm-wheel hub is provided with clutchteeth 71., with which theclutch-teeth G on the sleeve G may be engaged. Finally, below theworm-wheel hub H the feed-screw D is embraced by a nonthreaded butsplined sleeve I, which rotates in a bearing in the bottom plate A ofthe swivel-frame A and carries a fixed pinion I. (See Fig. 13.)

Back of and parallel with the feed-screw D is rotatably supportedadrivingshaft J, Figs. 1, 2, 5, and 6, having its upper bearing in thecross-girt a at the top of the guide-pillars A and its lower end steppedin the stirrup J, Fig. 5. The shaft J is provided with a fast beveledpinion 7J which meshes with the pinion'B on the engine-shaft B. It isalso provided with a sliding pinion J which rotates with the shaft bymeans of a spline, Fig. 2, and which meshes with the pinion e, thatdrives the drill-rod chuck. The hub of said pinion J rotates in thecross-head A. Said shaft J is further provided with a loose pinion J"inposition to mesh with the pinion I J is a clutch splined on the shaftJ below the pinion J 4 and adapted to engage with the hub of saidpinion, as indicated in Fig. 6, to cause the latter to rotate with theshaft. Vertical movement is given to the clutch J 5 by means ofabranched hand-lever J pivoted at j, as shown in Figs. 1, o, and 6.Finally, the shaft J is provided with a fixed pinion J immediately aboveits bearing in the upper cross-beam of the swivel-head.

K is a counter-shaft parallel with the shaft J and supported in longbearings in the upper part of .the swivel-head. It carries at the upperend a fast pinion K, which meshes with the pinion J 7 on thedriving-shaft J, and at its lower end within the shell of -theswivelhead it is provided with abeveled pinion K which meshes with abeveled pinion L on a horizontal feed-shaft L. (Shown in side view inFigs. 5 and 10, in end view in Figs. 1 and 11, and in dotted lines inFig. 6.)

The shaftL carries three loose pinions L L L of unequal diameter, asshown in Fig 5, which mesh with the three pinions M, M, and M fixed onthe sh'aft'M, which is arranged below the shaft L and paralleltherewith, as also shown in Fig. 5. The shaft M is provided with a wormM, which engages the worm-wheel H on the sleeve H, and said shaft willhereinafter be referred to as the worm-shaft. As a means of driving theworm-shaft from the shaft L through the medium of either one of theloose pinions'L L L, according to the'speed which it may be desired togive to the worm-shaft, said shaftL is made hollow, as shown in Fig-10,and is provided with a slot or opposite slots L in that portion embracedby the pinions L L and L as shown in Fig. 12.. Into the endof the hollowshaft L is inserted a shaft recesses Z for a part of their thickness,within which recesses the protruding key Z maystand and rer'olve withoutcarrying the adjacent pinion with it; but each of said pinions for,

the remainder of its thickness is provided with slots or notches Zadapted to receive the key Z, so that when occupied by said key thepinion containing the key is made fast with the shaft and is rotatedtherewith. The inner or most remote pinion'L of the series is alsoprovided with notches Z for engagement with the movable key Z.

In the sectional view, Fig. 10, the movable key is shown engaged withthe smallest pinion L of the driving series, and said pinion istherefore locked with the driving-shaft L and is ro- V tated therewith,giving the lowest speed provided for to the worm-shaft. By drawing outthe key into the next recess Z the shaftL and its key Z, together withthe key-shaft L will rotate without carrying either of the pinions, andthe same is true when the key occupies the recess in the outer or largerpinion L By means of this shifting key either of the driving-pinions maymanifestly be engaged,

at pleasure. In order that the key-shaft L may be drawn out or pushed inwhile the shaft L is running, the handle L on the shaft L is swiveledthereto, and said handle is kept from rotation by means of a projectionl thereon, which runs in a groove Z in the subjacent part of the framewhich forms the bearing for the worm-shaft. (See Figs. 1, 5, and 10.)

Vith the foregoing description of the gearing and with the understandingthat the drillrod 0 carries at its lower end arotar-y cutterhead 0 ofany description suitable for either drilling or reaming, and that uponthe lower reduced and screw-threaded end D of the feed-screw D acasing-tube D may be at tached, I will proceed to describe the mode ofoperation by which the machine does its work.

As before stated, the main horizontal shaft B is rotated by the engine,and its direction of motion for the advance of the drill-rod when thefeed-screw D is left-handed, as shown, will be from right to left, asindicated by the arrow applied to said shaft in Figs. 5 and G. Thisgives amotion from left to right to the vertical shaft J, as indicatedby the arrow applied to the hub of the beveled wheel J in Fig. 5. Theshaft J, through the pinions J 3 and e, gives a motion in a contrarydirection, or from right to left, to the drill-rod O, as shown by thearrow applied to the pinion e in Fig. 1 and to the drill-rod C in Fig.

2 and in other figures of the drawings.

The feed-screw D has a motion from left to right, (or in a directionopposite to that of the drill-rod.) which is imparted to it through theworm M worm-wheel H, and clutch G when the latter is lowered intoengagement with the worm-wheel hub H. In this position of the clutch Gthe arm G2 011 the clutch-lever G is engaged with one of the notches fin the flange f on the feed-nut F, by which engagement said feed-nut isheld from rotation. The thread on the feed-screw D being lefthanded orrunning downward from right to left, this left to right rotary motion ofthe feedscrew runs the latter downwardly through the stationaryfeed-nut, the speed of such downward feed depending upon which pinion ofthe series L L L is locked to the shaft L by the sliding key Z. In thisdownward movement of the feed-screw D the drill-rod O is carried down atthe same speed through the connection of the feed-screw with thedrillrod by means of the roller thrust-bearing E sleeve E, and chuck E,Fig. 2. The casing attached to the lower end of the feed-screw D willtherefore descend into the hole at the same speed of descent as thedrill-rod, so that the hole will be made or reamed at the same time andwith the same rapidity that the easing is inserted therein. When theclutch G position by raising the clutch-lever J so as to bring thesplined clutch J 5 into engagement with the pinion J 4 and thus causethe latter to rotate with the shaft J. This connection runs theleft-handed feed-screw D rapidly upward through the stationary nut F andwithdraws the casing and the drill-rod from 'the hole. Retainingthedriving engagement between the pinions J and I, as just described,and throwing the clutch G upward into engagement with the nutF (which atthe same time releases said nut by withdrawing the arm G2 of theclutch-lever from engagement with the flange f of said nut) cause thefeed-nut to 1'0- tate from right to left with the same velocity as thatof the feed-screw, and as a consequence the drill and the casing willberotated in the hole without either upward or downward movement. Thissingle rotary movement is often desirable for the purpose of keeping thedrill-rod or casing free in the hole preparatory to its being advancedor withdrawn thereafter, as occasion may require.

By connecting the casing D with the feedscrew D through aswivel-coupling, one form of which is shown at N, Fig. 14:, the casingmay obviously be thrust down or drawn out without rotation thereof.

' Manifestly the clutch G cannot be engaged with the worm-hub H at thesame time that the clutch J 5 is engaged with the pinion J since therotary motion given to the feedscrew by one of these drivers is oppositethat given it by the other.

The construction above described, wherein the casing D is turned in adirection opposite that of the drill-rod, involves an importantimprovement, for reasons as follows: The casing and drill-rod arenecessarily revolved in a direction to tighten the screwjointsconnecting the short sections composing said casing and drill-rod. Thecasing is either forced downwardly with the drill without rotation orturned at a slow rate of speed .relatively to the drill-rod, it usuallybeing desirable that the casing should revolve as it descends in orderto keep in motion the loose material surrounding it, and thisfacilitates its descent. It has been found, however, that when thescrew-joints connecting the sections of the casing and drill-rod arealike or are both provided with right-hand or left-hand threads therapid rotation of the drill-rod within the casing produces such a rapidwhirling of the water therein as to finally rotate and unscrew the lowersections of the casing to an extent sufficient to cause the completedetachment of the same, and this is liable to take place either when thecasing is sunk without rotation or is turned at the usual speed in thesame direction with the rod. The detachment of the lower casing-sectionsin the bored hole is a matter of serious inconvenience, and to avoidliabilityof such an occurrence I rotate the casing and drill-rod inopposite directions, as above pointed out, of course making thescrew-joints of the casin g anddrill-rodright and left'handed tocorrespond with the direction in which the parts. 7 are driven.v Theaction of the rapidly-revolvby which the said parts are fed downwardlyat the same speed and are at the same time capable of independentrotation.

The main features of construction above referred to may be carried outby the use of an apparatus dilfering greatly in its details from thatherein illustrated. Forinstance, as far as the turning of the drill-rodand casing in opposite directions and the feeding of both the drill-rodand easing by a single feedscrew is concerned, the gearing for turningthe casin g may act upon the casing otherwise than through the saidfeed-screw. Many of the particular details of construction herein shownin themselves embrace important improvements and are herein claimed aspart of my invention as, forinstance, in the machine illustrated thecasing is directly at tached to and is driven at the same speed as thefeed-screw,therebyrenderingunnecessary a separate driving-gear forturning the casing, and this feature of the ma'chineis herein claimed asa separate improvement.

Another branch of myimprovement relates to the indication by the machineof the relation between the downward force exerted by the weight of thedrill-rod and casing to the resistance opposed by the rock or'earth tothe downward movement of said drill-rod and casing. Such indications arehere illustrated as being obtained by means of the vertically-.

movable feed-nut F, two separate indicators F F and intermediatemechanism by which the vertical movements of the feed-nut aretransmitted to the pointers on said indicators. For this purpose thecross-plate A of the swivel-head is provided with two downwardly-openingchambers F F one at each side'of the central passage for the feed-nut,on the lower side of said cross-plate, and with two correspondingchambers F F in similar positions in the upper part of said cross-beamand opening'upwardly. The two chambers of each pair are connected by apassage f3, Fig. 7, and to each chamber is closely fitted a plunger Fwhich projects beyond the adjacent surface of the cross-plate. Ayokeplate F is supported by the flange fon the lower end of the feed-nutand bears upwardly.

against the lower plungers F and a similar yoke-plate F rests upon theupper plungers F and is secured upon the upper end of the feed-nut bymeans of a nut or similar device figure on its dial.

' F 'As shown by dotted lines in Fig.9, the

lower pair of chambers F communicates with the gage or indicator F,and,as seen by dotted lines at the right in said figure, the upper pairof chambers F communicates with the indicator F The chambers and tubesconnecting therewith are occupied by oil, glycerine, or other similarfluid, and as a result an upward movement of the feed nut F will advancethe pointer on the indicator F, while a downward movement of saidfeed-nutwill similarly advance the pointer on the indicator F Inasmuchas this feed-nut on the one hand takes the upthrust of the drill-rod andfeedscrew, which results mainly from the resistance of the rock to thedrill, and on the other hand takes the downthrust of the weight-of thedrill-rod and the casing, it is manifest that the relations of these twoforces which act to give a vertical movement of the feednut outof itsnormal or practically-poised position may at all times be judged byinspection of the indicators. Thus when the hole is just started and buta single length or a few lengths only of drill-rod ,and easing areconnected with the feed-screw the nut will be lifted above its normal orpoised position, because the downwardly feeding force will nearly orpractically equal the total resist-' ance encountered by the'drill, andthe indicator F will register a correspondingly high On the other hand,when the hole is deep and the weight of the drillrod and easing exceedsthe force required to overcome the resistance of the rock the feednutwill stand below its normal or poised position, and the indicator F willregister a correspondingly high figure on its dial. WVhen the drill-rodand casing are of such. length as to equal the average resistanceof'ythe rock, the indicators will both jump alternately as ICU theresistance varies. The principal utilities of these indicators are,first, their revelation to the operator of the character or hardness ofthe rock or other material in which the drill is at work, by which. hemay adj ustthe rate of feed to the hardness of the rock or to resistanceof the work, and, second, the signal they give of the passage of thedrillfrom one stratum to another and from rock into a cavity. Theconstruction described, wherein a plurality of connected chambers islocated in the cross-plate of the frame, has the ad vantages of allowingthe pistons to be made tight, of keeping in practical working order inthe continued operation of the machine, and of always giving the fullestindication with an almost imperceptible movementot' the feed-nut.

In a prior patent, No. 165,539, dated July 13, 1875, I have shown anddescribed a rockdrilling apparatus having in its frame annular chamberscontaining annular pistons which are connected with a feed-nut and twopressure-gages connected with the chambers for the purpose of indicatingthe relation between the downward pressure exertedby the weight of thedrill-rod and the resistance to the advance of the drill-rod caused bythe rock and earth. The device for this purpose herein described is inthe nature of an improvement on that set forth in the prior patent,which has been found defective in several particulars, but principallyfrom the fact that it is exceedingly difficult to make a tight jointwith an annular piston of the character illustrated in said patent. Byemploying a plurality of small pistons, as herein illustrated, a muchmore simple and economical construction is obtained and any diflicultywith the packing of the pistons is entirely obviated.

' A further improvement relates toa support of the swivel-head inaddition to that which it derives from the engine-frame. The swivelplatewhich directly connects the head with the engine-frame is at the rearpart of the swiveled frame, and the weight of the drillrod and easingwhen long gives in the overhanging position of these parts a formidabledownward strain upon the connection of the frame with the engine inlifting or lowering them. To obviate this difficulty I have shown inFig. 1 removable legs 0 O, fitted at their upper ends to the front undersurface of the swivel-frame and desirably held in place by bolts 0 0, asindicated, or in some other suitable manner. They stand in the same orpractically the same plane with' the feedscrew, and therefore whollytake off the overhanging strain referred to.

The roller thrust-bearing above designated as a whole by the letter Ehas, as here shown, the novel feature of giving compressive strain uponthe rollers in both upward and downward thrusts. It consists,essentially, of two apertured and relatively-rotatable parts, betweenthe transverse and proximate surfaces of which are insertedfriction-roliers, each of the two parts mentioned being extended bothabove and below the rollers. The manifest advantage of such constructionis to allow of rotation with equal case whether the thrust be upward ordownward. Referring to Fig. 8 as illustrating this hearingcoupling mostclearly, the sleeve E (which is the upper of the two principal membersof the bearing) is extended downward beyond the rollers E and isprovided above them with the projecting flange E and below them with theprojecting nut E each reaching outwardly about half the length of therollers. The lower member consists of the annular part E, which rises tothe upper surface of the nut E beneath the rollers, and the part E whichat its upper edge extends inwardly to form an annular flange e over theouter half of the rollers opposite the flange E Between the rollers andthe upper flanges E and e is inserted .a bearing-ring e, and between therollers and the subjacent parts and E is interposed a similar ring e Inthis construction it is plain that the downthrust of the sleeveE-through its flange E is opposed by the part E, while the upward pullof the sleeve E or the downward pull of the casing through the member EE is taken by the nut E and the flange 6 In both cases the rollers E aresubjected to compression between the bearing-rings 6' and c and saidbearing-rings distribute over the whole length of the rollers the strainwhich they receive at their outer or inner portions only. The steel ring6 serves merely to confine the rollers E in place. One of the twoshoulders or flanges of each principal memberbeingmovablewith respect tothe other, as indicated by the screwthreads by which said shoulders orparts of each member are shown connected in the drawings, the bearin gmay be adjusted to any degree of closeness. Such screw -th readedconnection of the parts also permits the thrust-coupling containing therollers and bearing-rings to be joined when made of continuously-annularparts, as shown.

. IVishing it to be understood that I am not restricted to theparticular devices here1n illustrated and described, and reserv ng theright to claim in a separate application for patent the novel methodsand other matters herein set forth but not claimed below, I claim as myinvention- 1. A rock or earth drilling apparatus comprising a drill-rod,a casing, gearing which rotates the drill-rod in one direction, and agearing which rotates the casing in the opposite direction.

2. A rock or earth drilling apparatus comprising a drill-rod, acasing-tube, a verticallystationary feed-nut, a feed-screw threadedthrough the feed-nut, a thrust-bear ng rotatably connecting thefeed-serewwrth the drill-rod, a gearing applied to rotate the drilltoorod, and a gearing whichrotates the casingtube.

3. A rocker earth drilling apparatus comprising a drill-rod, acasing-tube, a verticallystationary feed-nut, a feed-screw threadedthrough the feed-nut,'a thrust-bear ng connecting the feed-nut with thedrill rod, gearing turning the feed-screw, and gearing turning thedrill-rod, said feed-screw being attached to the casing-tube so as toboth turn and advance the latter, substantially as described.

4. A rock or earth drilling apparatus comprising a drill-rod, acasing-tube, a verticallystationary feed-nut, a feed-screw threadedthrough the feed-nut, a drill-chuck having rotatable connection with thefeed-screw and engaging the drill-rod, and gearing turning thedrill-chuck and feedscrew independently of each other. I r

5. In a rock-drill, the combination, with guides and a cross-head fittedto move thereon, of a sleeve mounted rotatably in the cross head, adrill-chuck attached to the upper end of the sleeve, a tubularthrust-bearing or coupling having relatively-rotatable parts attached tothe lower end of the sleeve, a tubular feed-screw attached to the lowerpart of IIO the thrust-bearing and having the drill tended through it, afeed-nut supported by the frame, and a rotating d rivin g-shaf t gearedwith the sleeve to which is attached the drillchuck and th rust-beari ng.

(3. The combination, with a drill-rod, a feedscrew, and a feed-nutsupported in a frame and embracing the feed -screw, of a gearing forrotating the feed-screw at a slow speed for the working operation of thedrill, a second gearing for rotating the feed-screw at a relatively highvelocity for rapidly raising and loweringthe feed-screw, and means forconnecting and disconnecting either set of gearing with and from thefeed-screw at will.

'7. The combination, with the frame of a rock-drill, of afeed-nutsupported in the frame, a tubular f ee'd-screw threaded throughthe feed-nut, a drill-chuck rotatablyconnected with the feed-screw,gearing which rotates the drill-chuck in one direction, gearing forrotating the feed-screw in both directions, and means for throwing saidgearing into and out of engagement with the feedscrew.

S. The combination, with the frame of a rock-drill, of a feed-nutsupported by the frame, a tubular feed-screw passing through thefeed-nut, a gear-sleeve I-I, rotatably embracing the feed-screw, aclutch splined to the feed-screw and movable into and out of e11-gagement with the gear-sleeve, a gear-sleeve I, splined on thefeed-screw, a drill-rod passing through the feed-screw, connectedtherewith by a thrust-bearing having relatively-rotatable parts,mechanism for rotating the drillrod, gearing for driving the sleeve Hand the sleeve I successively in opposite directions, and means forshifting the gear-connections.

9. The combination, with the frame of a rock-drill, of a. feed-nutsupported by the frame, a tubular feed-screw passing through thefeed-nut, a gear-sleeve I1, rotatably embracing t-he feed-screw,a clutchG, splined to the feed-screw and movable into and out of engagement withthe gear-sleeve, a gear-sleeve I, splined on the feed-screw, a drill-rodpassing through the feed-screw and connected therewith by athrust-bearing having relativelyrotatable parts, a casing-tube connectedwith the feed-screw, mechanism for rotating the drill-rod, gearing fordriving the sleeve H and the'sleeve I successively in oppositedirections, and means for shifting the gearconnections. v

10. The combination, with the frame of a rock-drill, of a rotatablefeed-nut supported by the frame, a tubular feed-screw passing throughthe feed lfut, a drillrod passing through the feed-screw and connectedtherewith by a thrust-bearing having relativelyrotatable parts, by oneof which it connects with the drill-chuck and by the other of which itconnects with the feed screw, a gear-sleeve II, embracing the feedscrew, a clutch G, splined to the feed-screw and movable into and out ofengagement with the gear-sleeve II, a lock by which the feed-nut may beheld from rotation when the clutch is engaged with the worm-sleeve, asplined gear-sleeve I on the feed-screw, driving-gear for rotating thedrill-rod, variable-speed gearing for driving the gear-sleeve H, anddisengageable gearing for driving the gear-sleeve I.

11. The combination, with the frame of a rock-drill, of a rotatablefeed-nut supported by the frame, a tubular feed-screw passing throughthe feed-nut and adapted to be connected with a casing-tube, a drill-rodpassing through the feed-screw and connected therewith by athrust-bearing having relatively rotatable parts, by one of which itconnects with the drill-chuck and by the other of which it connects withthe feed-screw, a gear-sleeveembracing the feed-screw, a clutch splinedto the feed-screw and movable into and out of engagement with thegear-sleeve H, a lock by H, and disengageable gear for driving the.

gear-sleeve I.

12. The combination, with the frame, of a feed-screw, a rotatablefeed-nut, a worm-gear H, rotatable on the feed-screw, a clutch G,adapted to engage both the feed-nut, and the worm-sleeve, a lever formoving the clutch G, carrying a locking device for engagement with thefeed-nut when the clutch is at or below its mid-position, a splinedgear-sleeve I, gearing for driving the sleeve H, gearing for'driving thesleeve I, and means for shifting the gearing connections.

13. The. combination, with the feedscrew and the verticallymovablefeed-nut, of a cross-plate of the frame provided with a plurality ofconnected upwardly-opening chambers and a plurality of connecteddownwardlyopening chambers containing a liquid, a plurality of separatecircular pistons movably fitted to the several chambers and connectedwith the feed-nut, and two pressure-gages connected one with theupwardly-opening and the other with the downwardly-openin g chambers.

14. The combination, with the feed-screw and with the frame providedwith aplurality of upper chambers F and a plurality of lower chambers Fof a vertically-movable feed-nut, a plurality of separate circularpistons F protruding from the chambers, cross-plates F F connecting thefeed-nut with the pistons, and two gages connected with the several setsof chambers, the latter being occupied by a suit able liquid.

15. In a-variable-speed feed-gear for rock or earth drills, thecombination, with the drill-rod, feed-screw, and a swivel-headsustaining the same, of an intermediate shaft L, mounted in theswivel-head transversely to the feed-screw and drivin g-shaft andprovided with a series o'f'loose unequalpinions having interiorfeather-ways, an annular recess between the feather-way of each pinionand that of the next pinion,alengthwise-movable part L, provided with akey adapted to engage the feather-ways and to revolve in the annularrecess,-a counter-shaft mounted in the head parallel with thefeed-screw, bevelgears connecting the counter-shaft with said shaft L, ashaft M, parallel with the shaft L and provided with a reversed seriesof unequal fast pinions meshed with those on the shaft L, and a worm onsaid shaft engaged with the worm-wheel on the feed-screw, substantiallyas described.

16. The combination, with the main frame of a rock or earth drill, of aswivel-h ead rotatably supported thereon and a removable support orsupports fitted beneath the outer part of the swivel-head to aid insustaining the weight of the drill-rod and other suspended parts.

17. A thrust-bearing for uniting the drillrod chuck and the feed-nut orother parts to be similarly connected, comprising two members one havingtwo outwardly and the other two inwardly projecting flanges,bearing-rings engaging the projections of both members, and rollersinserted between the bearingrings.

18. The combination, with a member E, provided with a fixed flange and amovable flange E of a member composed of adjustable parts Eand Epresenting inwardly-directed flanges or surfaces, rollers 13*, andbearingrings 6 and 6 above and below the rollers, said rollers and thebearing-rings being confined between the upper and lower flanges of bothmembers, substantially as described.

Intestimouy that I claim the foregoing as my invention I affix mysignature in presence of two witnesses.

MILAN O. BULLOCK.

Witnesses:

M. E. DAYTON, C. CLARENCE Poona,

